in the form as they appear in their main text but using
the notation here (Eq. (17) and Eq. (20) in Ref. [1]}).
Rewriting these in terms of binary entropy gives
\(\chi \left(\check{\mathcal {S}}:\mathcal {F}\right)=h\left[\frac{1}{2}\left(1+\sqrt{1-4p_{1}p_{2}\left(1-\left|\gamma \right|^{2{^{\sharp }}\hspace{-1.99168pt}\mathcal {F}}\right)}\right)\right],\) 
